RESUMO
<p><b>OBJECTIVE</b>To determine the postnatal changes in serum neuron-specific enolase (NSE) level in neonates.</p><p><b>METHODS</b>Twenty full-term infants and 30 preterm infants without a history of asphyxia or neurological disease born over the same period were enrolled. The 30 preterm infants consisted of 15 late preterm births and 15 early preterm births. Serum NSE levels were determined using electrochemical immunosensor array on postnatal days 1, 3 and 7. Ten healthy adults volunteered as controls.</p><p><b>RESULTS</b>Serum NSE levels in neonates of the full-term group and two preterm groups gradually decreased with increasing birth age (P<0.01). All the three groups of neonates had significantly higher serum NSE levels on postnatal days 1, 3, and 7 than the healthy adult group (P<0.01). The early preterm group had significantly higher serum NSE levels than the full-term group on postnatal days 1, 3, and 7 (P<0.01).</p><p><b>CONCLUSIONS</b>Serum NSE level in neonates during early postnatal days is related to gestational and birth ages and higher than the normal adult level. The reference value for normal serum NSE level in neonates should be determined according to gestational and birth ages, rather than the normal adult level.</p>